An excimer is a short-lived molecule which typically consists of two atoms in an excited or high-energy state. An excimer may include atoms which will not normally bond with one another in the unexcited or ground state. As set forth in U.S. Pat. No. 6,400,089, (“the '089 patent”) the disclosure of which is incorporated by reference herein, excimers can be generated efficiently by applying an electric field to a gas capable of forming excimers as, for example, noble gases and providing free electrons in the gas. For example, the field may be provided between a first electrode and a counter electrode immersed in the gas. The electric field is configured to accelerate electrons to at least the energy required to form excimers, but is configured so that in at least one region of the field, the field strength is below that required to substantially ionize the gas. Therefore, an arc does not form between the first electrode and the counter electrode. Such a non-arcing discharge is referred to as a corona discharge.
This arrangement can be used in creation of excimers for any purpose. One particularly useful application is in formation of excimers which emit electromagnetic radiation such as light upon decay of the excimers. For example, certain noble gas containing excimers will emit ultraviolet light upon decay. If the wall of the chamber is transparent or translucent to the light generated by decay of the excimers, the light can pass out of the chamber. Certain devices according to the '089 patent can provide intense ultraviolet light.
Despite the advance in the art represented by the '089 patent, still further improvement would be desirable.